The present invention generally concerns the production of synthetic gas or fuel gas containing hydrogen and carbon monoxide which is formed by partially oxidizing a slurry of solid carbonaceous fuel and a carrier liquid admixed with a gas containing free oxygen in a hollow free-flowing reactor. More particularly, this invention concerns an improved burner nozzle for admixing the slurry and the oxyen-containing gas, and then introducing the admixture into a reactor.
Three basic processes have been developed for the gasification of carbonaceous materials. They are the fixed bed process, the fluidized bed process, and the suspension or entrained process. The efficiency of the entrained process, with which the present invention is concerned, is significantly affected by the degree of mixing of reactants prior to carrying out the partial oxidation reaction leading to gasification. Where a slurry of a finely divided carbonaceous fuel in a carrier liquid is admixed with an oxygen-containing gas, it is very important that the reactants are uniformly mixed and atomized into very fine droplets at the time they are vaporized and then ignited to form a gaseous product. Annular-type burner nozzles have been employed for introducing an admixture of slurry and oxygen-containing gas into a reactor. For example, annular-type burners are shown in U.S. Pat. Nos. 4,364,744 and 4,443,230. Problems that have been addressed with such burner nozzles include mixing to provide proper distribution of the fuel and oxygen in the admixture, atomization of the admixture, stability of burner nozzle operation, reduction of localized overheating in the reactor and burner nozzle, and reduction of mechanical wear of the burner nozzle. In addition to these problems, slurries containing a high concentration of divided solids also tend to plug or partially plug annular passageways as they are transported through the burner nozzles.